BUG: pd.show_versions: json.decoder.JSONDecodeError

doc/source/whatsnew/v1.3.0.rst

@@ -478,6 +478,7 @@ Other
 - :class:`Styler` rendered HTML output minor alterations to support w3 good code standard (:issue:`39626`)
 - Bug in :class:`Styler` where rendered HTML was missing a column class identifier for certain header cells (:issue:`39716`)
 - Bug in :meth:`DataFrame.equals`, :meth:`Series.equals`, :meth:`Index.equals` with object-dtype containing ``np.datetime64("NaT")`` or ``np.timedelta64("NaT")`` (:issue:`39650`)
+- Bug in :func:`pandas.util.show_versions` where console JSON output was not proper JSON (:issue:`39701`)
 
 
 .. ---------------------------------------------------------------------------

pandas/tests/util/test_show_versions.py

@@ -1,7 +1,14 @@
+import json
+import os
 import re
 
 import pytest
 
+from pandas.util._print_versions import (
+    _get_dependency_info,
+    _get_sys_info,
+)
+
 import pandas as pd
 
 
@@ -26,11 +33,47 @@
     "ignore:Distutils:UserWarning"
 )
 @pytest.mark.filterwarnings("ignore:Setuptools is replacing distutils:UserWarning")
-def test_show_versions(capsys):
+def test_show_versions(tmpdir):
+    # GH39701
+    as_json = os.path.join(tmpdir, "test_output.json")
+
+    pd.show_versions(as_json=as_json)
+
+    with open(as_json) as fd:
+        # check if file output is valid JSON, will raise an exception if not
+        result = json.load(fd)
+
+    # Basic check that each version element is found in output
+    expected = {
+        "system": _get_sys_info(),
+        "dependencies": _get_dependency_info(),
+    }
+
+    assert result == expected
+
+
+def test_show_versions_console_json(capsys):
+    # GH39701
+    pd.show_versions(as_json=True)
+    stdout = capsys.readouterr().out
+
+    # check valid json is printed to the console if as_json is True
+    result = json.loads(stdout)
+
+    # Basic check that each version element is found in output
+    expected = {
+        "system": _get_sys_info(),
+        "dependencies": _get_dependency_info(),
+    }
+
+    assert result == expected
+
+
+def test_show_versions_console(capsys):
     # gh-32041
-    pd.show_versions()
-    captured = capsys.readouterr()
-    result = captured.out
+    # GH39701
+    pd.show_versions(as_json=False)
+    result = capsys.readouterr().out
 
     # check header
     assert "INSTALLED VERSIONS" in result
@@ -44,3 +87,16 @@ def test_show_versions(capsys):
 
     # check optional dependency
     assert re.search(r"pyarrow\s*:\s([0-9\.]+|None)\n", result)
+
+
+def test_json_output_match(capsys, tmpdir):
+    # GH39701
+    pd.show_versions(as_json=True)
+    result_console = capsys.readouterr().out
+
+    out_path = os.path.join(tmpdir, "test_json.json")
+    pd.show_versions(as_json=out_path)
+    with open(out_path) as out_fd:
+        result_file = out_fd.read()
+
+    assert result_console == result_file

pandas/util/_print_versions.py

@@ -115,7 +115,7 @@ def show_versions(as_json: Union[str, bool] = False) -> None:
         j = {"system": sys_info, "dependencies": deps}
 
         if as_json is True:
-            print(j)
+            sys.stdout.writelines(json.dumps(j, indent=2))
         else:
             assert isinstance(as_json, str)  # needed for mypy
             with codecs.open(as_json, "wb", encoding="utf8") as f: